bazarr/libs/chardet/charsetgroupprober.py

107 lines
3.8 KiB
Python

######################## BEGIN LICENSE BLOCK ########################
# The Original Code is Mozilla Communicator client code.
#
# The Initial Developer of the Original Code is
# Netscape Communications Corporation.
# Portions created by the Initial Developer are Copyright (C) 1998
# the Initial Developer. All Rights Reserved.
#
# Contributor(s):
# Mark Pilgrim - port to Python
#
# This library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation; either
# version 2.1 of the License, or (at your option) any later version.
#
# This library is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with this library; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
# 02110-1301 USA
######################### END LICENSE BLOCK #########################
from typing import List, Optional, Union
from .charsetprober import CharSetProber
from .enums import LanguageFilter, ProbingState
class CharSetGroupProber(CharSetProber):
def __init__(self, lang_filter: LanguageFilter = LanguageFilter.NONE) -> None:
super().__init__(lang_filter=lang_filter)
self._active_num = 0
self.probers: List[CharSetProber] = []
self._best_guess_prober: Optional[CharSetProber] = None
def reset(self) -> None:
super().reset()
self._active_num = 0
for prober in self.probers:
prober.reset()
prober.active = True
self._active_num += 1
self._best_guess_prober = None
@property
def charset_name(self) -> Optional[str]:
if not self._best_guess_prober:
self.get_confidence()
if not self._best_guess_prober:
return None
return self._best_guess_prober.charset_name
@property
def language(self) -> Optional[str]:
if not self._best_guess_prober:
self.get_confidence()
if not self._best_guess_prober:
return None
return self._best_guess_prober.language
def feed(self, byte_str: Union[bytes, bytearray]) -> ProbingState:
for prober in self.probers:
if not prober.active:
continue
state = prober.feed(byte_str)
if not state:
continue
if state == ProbingState.FOUND_IT:
self._best_guess_prober = prober
self._state = ProbingState.FOUND_IT
return self.state
if state == ProbingState.NOT_ME:
prober.active = False
self._active_num -= 1
if self._active_num <= 0:
self._state = ProbingState.NOT_ME
return self.state
return self.state
def get_confidence(self) -> float:
state = self.state
if state == ProbingState.FOUND_IT:
return 0.99
if state == ProbingState.NOT_ME:
return 0.01
best_conf = 0.0
self._best_guess_prober = None
for prober in self.probers:
if not prober.active:
self.logger.debug("%s not active", prober.charset_name)
continue
conf = prober.get_confidence()
self.logger.debug(
"%s %s confidence = %s", prober.charset_name, prober.language, conf
)
if best_conf < conf:
best_conf = conf
self._best_guess_prober = prober
if not self._best_guess_prober:
return 0.0
return best_conf